621146861 has 4 divisors (see below), whose sum is σ = 637934652. Its totient is φ = 604359072.

The previous prime is 621146821. The next prime is 621146863. The reversal of 621146861 is 168641126.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 168641126 = 2 ⋅84320563.

It can be written as a sum of positive squares in 2 ways, for example, as 358382761 + 262764100 = 18931^2 + 16210^2 .

It is a cyclic number.

It is not a de Polignac number, because 621146861 - 2⁶ = 621146797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621146863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8393840 + ... + 8393913.

It is an arithmetic number, because the mean of its divisors is an integer number (159483663).

Almost surely, 2^621146861 is an apocalyptic number.

It is an amenable number.

621146861 is a deficient number, since it is larger than the sum of its proper divisors (16787791).

621146861 is a wasteful number, since it uses less digits than its factorization.

621146861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16787790.

The product of its digits is 13824, while the sum is 35.

The square root of 621146861 is about 24922.8180790215. The cubic root of 621146861 is about 853.2273435898.

Adding to 621146861 its reverse (168641126), we get a palindrome (789787987).

The spelling of 621146861 in words is "six hundred twenty-one million, one hundred forty-six thousand, eight hundred sixty-one".